Olivine is one of the most abundant minerals on Earth and one of the most versatile, with uses stretching from blast furnaces to jewelry boxes and, increasingly, into climate technology. Global production of olivine-bearing rock was roughly 8.4 million metric tons per year as of 2017, most of it mined from dunite deposits for steelmaking and refractory applications.1IOP Publishing. Energy demand and savings opportunities in the supply of limestone and olivine-rich rocks for geochemical carbon dioxide removal But the mineral’s story is broader than heavy industry. Its gem-quality variety, peridot, has been prized since antiquity. And in the past two decades, olivine has attracted intense scientific interest as a potential tool for pulling carbon dioxide out of the atmosphere.
The Workhorse Role in Steel and Refractories
The largest share of commercially mined olivine goes to metallurgy. In steelmaking, crushed olivine serves as a fluxing agent in blast furnaces, helping to strip impurities from molten iron. Its high melting point and chemical stability also make it a go-to material for refractory linings, the heat-resistant layers inside furnaces, kilns, and foundries that must withstand extreme temperatures without degrading. Forsterite-rich olivine (the magnesium-heavy end of the mineral’s compositional range) is especially valued here because of its thermal resilience. Commercially, the term “olivine” often encompasses not just the pure mineral but also olivine-bearing rocks like dunite and sometimes serpentinite, so production figures can be a little fuzzy.1IOP Publishing. Energy demand and savings opportunities in the supply of limestone and olivine-rich rocks for geochemical carbon dioxide removal
A Safer Abrasive for Blasting
Sandblasting with silica sand has long been a serious occupational health hazard because inhaling crystalline silica dust can cause silicosis, a chronic and sometimes fatal lung disease. That risk has pushed industry toward substitute abrasives that are less dangerous to workers. Olivine is one of the alternatives that NIOSH researchers have evaluated alongside coal slag, copper slag, garnet, staurolite, crushed glass, and steel grit.2CDC Stacks. Evaluation of substitutes for silica sand in abrasive blasting Olivine’s angular grain shape makes it effective at stripping rust, paint, and mill scale from metal surfaces, and because it contains negligible free silica, it poses far less respiratory risk. It also has the practical advantage of being widely available and relatively inexpensive compared to some specialty abrasives. Shipyards, oil-and-gas facilities, and bridge maintenance crews are among the users who have shifted to olivine-based blasting media.
Enhanced Weathering for Carbon Capture
When olivine dissolves, it reacts with carbon dioxide and water, converting COâ‚‚ into dissolved bicarbonate. This is the same process that happens naturally when rain erodes silicate rocks over geologic time, gradually drawing down atmospheric carbon. The idea behind “enhanced weathering” is to speed that reaction up dramatically by grinding olivine into fine particles and spreading it where it can dissolve faster, on farmland, beaches, or directly into the ocean.
Laboratory experiments have confirmed the basic chemistry. In one set of seawater dissolution studies, adding olivine significantly raised the alkalinity of the water, which in turn drove additional COâ‚‚ absorption from the atmosphere.3PubMed Central. Olivine Dissolution in Seawater: Implications for CO2 Sequestration through Enhanced Weathering in Coastal Environments That is exactly what the concept predicts: dissolve the mineral, raise alkalinity, soak up more carbon. On paper, olivine’s magnesium-rich composition makes it one of the most promising minerals for this purpose because each unit that dissolves can neutralize a comparatively large amount of COâ‚‚.
The trouble is translating lab results into real-world performance. Under actual ocean or soil conditions, olivine dissolves much more slowly than it does in a controlled flask. Secondary minerals can form coatings on olivine grains, blocking further reaction. And the buffering chemistry of seawater itself limits how much extra carbon can be absorbed. One study modeling more realistic conditions found that COâ‚‚ uptake could be reduced by roughly a factor of five compared to idealized projections, suggesting olivine-based ocean weathering may be less efficient than early enthusiasm implied.4Frontiers in Climate. Kinetics of Olivine Weathering in Seawater: An Experimental Study Reliable estimates of how fast olivine actually dissolves in seafloor sediments remain elusive, with published values spanning orders of magnitude depending on local conditions.5PubMed Central. Negative CO2 emissions via enhanced silicate weathering in coastal environments
None of this means the idea is dead. It means the science is still catching up to the ambition. Pilot projects are underway on coastlines and farms in several countries, and researchers continue to refine the models that predict real-world dissolution rates. Enhanced weathering with olivine remains one of the more closely watched carbon-dioxide-removal strategies, even if the numbers are humbler than the original headlines suggested.
The Trace-Metal Caveat
Olivine naturally contains nickel and chromium, and any plan to spread millions of tons of crushed olivine across beaches or farmland has to account for what those metals do when they leach out. This is one of the stickier issues in the enhanced-weathering debate, and it tends to get overlooked in popular coverage.
Research focused on coastal settings has found that bottom-dwelling marine organisms face the highest risk from nickel exposure when olivine is mixed into surface sediments. Depending on the existing nickel concentrations in local sediment, safe application rates could be quite low, in some cases less than a kilogram of olivine per square meter of seabed.6PubMed. Deriving Nickel (Ni(II)) and Chromium (Cr(III)) Based Environmentally Safe Olivine Guidelines for Coastal Enhanced Silicate Weathering At gigaton scales, those limits could seriously constrain how much carbon can actually be captured via ocean-based weathering.
There is some nuance here. The weathering process itself releases magnesium and raises pH, both of which reduce nickel’s toxicity to organisms. Ecotoxicological modeling using biotic ligand models has shown that the chemical changes olivine weathering causes in surrounding water can significantly lower the predicted harm from the nickel it releases.7Minerals. Size-Fractionated Weathering of Olivine, Its CO2-Sequestration Rate, and Ecotoxicological Risk Assessment of Nickel Release Still, the broader environmental picture is complex. Beyond direct toxicity, researchers have flagged overlooked pathways: iron and potentially toxic metals released from olivine can interact with manganese oxides already present in sediments, potentially causing secondary contamination that initial risk assessments did not account for.8PubMed. Potential Environmental Impacts and Management Strategies for Metal Release during Ocean Alkalinity Enhancement Using Olivine Getting the environmental governance right will be just as challenging as getting the chemistry right.
Underground Carbon Mineralization
Enhanced weathering scatters olivine at the surface. A related but distinct strategy goes underground: injecting COâ‚‚-rich fluids into olivine-bearing rock formations deep below the surface, where heat and pressure accelerate the reaction and lock carbon into solid carbonate minerals permanently. This is sometimes called in-situ mineral carbonation.
The appeal is permanence. Unlike storing COâ‚‚ as a compressed gas in porous rock (which can leak), converting it into solid magnesite or calcite within olivine-rich formations produces a product that is geologically stable for millions of years. Experiments simulating subsurface conditions have studied olivine dissolution at elevated temperature and pressure, finding that reaction rates drop substantially over time as a silica-rich layer forms on grain surfaces and passivates them.9Chemical Geology. Olivine dissolution and carbonation under conditions relevant for in situ carbon storage That surface coating is one of the central engineering challenges: the mineral wants to armor itself against further reaction.
More recent work has explored how the interplay between dissolution and precipitation might actually help rather than hinder the process. Carbonation experiments have shown that etch pits and channels formed during dissolution could serve as starting points for micro-fractures, potentially cracking open fresh olivine surfaces and maintaining pathways for COâ‚‚-rich fluid to flow.10Chemical Geology. Interaction between dissolution and precipitation during olivine carbonation: Implications for CO2 mineralization If reaction-driven fracturing can be engineered reliably, it could transform olivine-rich underground formations into self-renewing carbon sinks. That is a big “if,” but it is the direction the research is heading.
Olivine on the Farm
Spreading crushed olivine on agricultural soils is a way to pursue carbon capture and soil improvement simultaneously. As olivine weathers in soil, it releases magnesium and silicon, both of which plants can use. A pot experiment growing ryegrass in olivine-amended soil found that plant growth increased by about 16% at the highest dose, with plant potassium concentrations rising as well. Magnesium and silicon uptake also went up.11PubMed Central. Olivine weathering in soil, and its effects on growth and nutrient uptake in Ryegrass (Lolium perenne L.): a pot experiment
The catch, as with the marine applications, is nickel. Olivine weathering in soil raised the bioavailability of nickel at every dose tested, and it also suppressed calcium uptake by the plants. For farmers, that means olivine cannot simply be dumped onto fields without limit. Application rates need to stay within bounds that avoid nickel buildup in the soil and in crops, and fields with low calcium availability would be especially vulnerable to nutritional imbalances. The research makes a practical case for olivine as a liming agent and slow-release fertilizer, but one that requires careful dosing rather than the heavy-handed spreading that some carbon-removal boosters have imagined.
Greener Concrete and Construction Materials
Cement production is one of the largest industrial sources of COâ‚‚, accounting for roughly 8% of global emissions. Olivine is finding a niche in efforts to decarbonize that sector. When olivine is dissolved in acid, the resulting amorphous silica is highly reactive and can serve as a supplementary cite material in cement, partially replacing the clinite that generates most of cement’s carbon footprint. Researchers have demonstrated that this silica product can be used to produce what they describe as carbon-negative cement and low-carbon concrete.12PubMed Central. Carbon capture and storage in low-carbon concrete using products derived from olivine
Beyond supplying reactive silica, the carbonation of olivine itself can yield magnesium carbonate products that are usable as construction aggregates or fillers. The concept is circular: dissolve or carbonate olivine, capture COâ‚‚ in the process, and use the resulting materials to make building products. Carbonated material derived from magnesium-silicate rocks could potentially produce construction materials that are net carbon-negative, meaning they store more COâ‚‚ in their lifetime than was emitted to make them.13Current Opinion in Green and Sustainable Chemistry. CO2 storage in cement and concrete by mineral carbonation This remains a developing area, but several startups and research groups are scaling up pilot production.
Heat Storage in Renewable Energy Systems
An application that gets less attention but has real potential is using olivine as a thermal energy storage medium. Concentrated solar power plants and industrial waste-heat recovery systems need materials that can absorb a lot of heat, hold it, and release it reliably. Olivine ticks several boxes: it is thermally stable at high temperatures, abundant, cheap, and nontoxic.
Peridotite, the rock composed largely of olivine, has been shown to maintain excellent thermal capacity at temperatures up to 500°C, with volumetric heat capacity values that make it competitive with purpose-engineered storage materials.14Journal of Energy Storage. Comprehensive experimental analysis of igneous ultra-mafic rocks as thermal energy storage materials In packed-bed systems, where granules of a filler material sit in a tank and absorb heat from a circulating fluid, olivine granules mixed with molten salt have demonstrated strong heat-storage density and stable discharge performance. One study evaluating different olivine-to-salt ratios found the fifty-fifty mix offered the best balance of conductivity and storage capacity for medium-temperature applications like textile drying.15Applied Thermal Engineering. Thermal characteristics study and evaluation of the packed bed thermal energy storage system with ternary nitrate salt mixture and olivine granules The cost advantage over synthetic ceramics or engineered phase-change materials could be substantial at scale.
Peridot, the Gem-Quality Variety
Olivine’s best-known public-facing role is as peridot, the bright yellow-green gemstone that happens to be August’s birthstone. Gem-quality peridot is essentially forsterite-rich olivine with just enough iron to produce that characteristic color but few enough inclusions to stay transparent. Unlike many gemstones, peridot forms deep in the mantle and reaches the surface through volcanic eruptions or tectonic uplift, rather than crystallizing in shallow hydrothermal veins.
The island of Zabargad (also called St. John’s Island) in the Egyptian Red Sea was the principal historical source of high-quality peridot in antiquity. Gemological analysis of peridots set in Byzantine and medieval reliquaries of the True Cross has traced their probable origin to that island, confirming a supply chain that stretched from the Red Sea to European ecclesiastical treasuries.16Journal of Raman Spectroscopy. Jewelled Byzantine and Medieval Reliquaries of the True Cross: Peridots and Other Gemstones in Material and Symbolic Perspective Today, commercial peridot comes primarily from deposits in Arizona, Myanmar, Pakistan, and China. Arizona’s San Carlos Apache Reservation remains one of the most productive sources in the world.
The gemstone’s value depends heavily on color saturation and clarity. The most prized stones are a rich, lime-to-olive green without brownish tints. Peridot is softer than sapphire or ruby, sitting around 6.5 to 7 on the Mohs scale, which makes it suitable for earrings and pendants but more vulnerable to scratching in daily-wear rings. Its relatively modest hardness and abundant supply keep prices low compared to the “big three” colored gemstones, which makes it an accessible entry point for collectors.
Synthetic Olivine Crystals for Research
Natural olivine crystals large enough and pure enough for certain laboratory measurements are hard to come by. Researchers need single crystals of known composition to study properties like thermal conductivity, elastic modulus, and how the mineral deforms under pressure. A technique adapted from the semiconductor industry, the Czochralski pulling method, has been used to grow synthetic olivine single crystals as large as 250 carats, providing material for anisotropic property measurements and controlled experiments that would be impossible with natural specimens.17Journal of Crystal Growth. First synthesis of olivine single crystal as large as 250 carats These lab-grown crystals are not cut into jewelry. They are research tools, used to understand how olivine behaves under the extreme conditions found deep inside the Earth.
Reading Earth’s Mantle Through Olivine
Olivine is the most abundant mineral in the upper mantle, and its physical behavior under stress is central to how geologists interpret seismic data. When the mantle flows, olivine crystals align preferentially along the direction of that flow, creating what geophysicists call crystallographic preferred orientation. That alignment makes the mantle anisotropic: seismic waves travel through it at different speeds depending on their direction. By measuring those speed differences at the surface, researchers can map mantle flow patterns thousands of kilometers away.
A database of 110 olivine fabric samples from a range of mantle environments, including oceanic plates, subduction zones, and kimberlite pipes, has shown that seismic anisotropy rises steeply with increasing crystal alignment and then levels off, reaching about 15 to 20% for compressional waves and 10 to 15% for shear waves.18Tectonophysics. An olivine fabric database: an overview of upper mantle fabrics and seismic anisotropy The crystal orientations most responsible for this anisotropy are well-characterized, giving seismologists a framework for converting wave-speed maps into pictures of how material moves beneath tectonic plates. Olivine alignment has even been observed during diffusion creep, a slow deformation mechanism that was previously thought not to produce preferred orientation, expanding the conditions under which mantle flow can be inferred from seismic observations.19PubMed. Olivine crystals align during diffusion creep of Earth’s upper mantle
Olivine Beyond Earth
Olivine is not just a terrestrial mineral. It has been identified on Mars, in cometary dust, and spectacularly in a class of meteorites called pallasites, which contain centimeter-scale olivine crystals embedded in an iron-nickel metal matrix. The Fukang pallasite, found in China’s Xinjiang province, is one of the most visually striking examples. Its olivine crystals contain distinctive arrays of parallel, straight, tubular inclusions that differ from anything seen in terrestrial olivine, offering clues about conditions deep inside the parent asteroid.20Meteoritics & Planetary Science. Tubular symplectic inclusions in olivine from the Fukang pallasite
The composition of olivine varies along a spectrum from magnesium-rich forsterite to iron-rich fayalite, and that ratio can be determined remotely using reflectance spectroscopy, a technique that analyzes the wavelengths of light bounced off a surface. Researchers have used this approach to characterize olivine deposits on Mars and on asteroids from orbit, mapping mineral compositions without ever touching a sample.21Journal of Geophysical Research: Planets. Determining the composition of olivine from reflectance spectroscopy Extraterrestrial olivine tells planetary scientists about the thermal and chemical history of bodies that formed alongside Earth over four billion years ago. When a pallasite slice turns up at a gem show, it is both a scientific artifact and an aesthetically stunning object, a reminder that olivine connects jewelry counters, steel mills, climate labs, and the deep interiors of other worlds.